I’m new to arduino, and I’m trying to figure out is it possible that arduino can turn on, and turn off a motor(gear motor 5.5kw 400v)with particular commands from a PC(currently that process is done with a PLC like in the picture, the PLC gets a command from a pc software and it turns on the motors, or off) But that PLC is extremely expensive , just for that 2 functions.
My idea would be to replace that plc with an arduino and those 24v relays on the right and fit some 5v relays that arduino could control.
And possibly those relays can control the contactors.
Thanks in advance.
The short answer is yes its possible, however you first need to take a close look at what you currently have and draw a proper wiring diagram so you can be certain that the existing PLC is only switching outputs, and isn't doing sensor scanning or E-stop functionality.
You also need to get hold of the PLC program to see if it has any timers to prevent short cycling, requires a specific startup order or time delay in relation to other motors, or has any specific time of day restrictions.
If the existing PLC really is just being used as a dumb switch then I personally would first look for a cheaper PLC and only go down the Arduino path as a last resort. Generally speaking industrial customers need industry standard gear that can be maintained and fixed by people with trade skills.
The PLC functions are: turn on and off the motors (2 motors to be exact), reading load cells, and reading inductive sensors(proximity sensors). No special functions only reading, no restrictions as you mentioned for the motors.
I’m not good at PLC programming and the ladders, I have the plc program but to convert it to another plc I think it would be a struggle.
That’s why I’m thinking about arduino
The cheapest PLCs I'm aware of are the Click series from Automation Direct. Talk to your local sales person and see if they can come up with a solution that is cheaper than what you currently have. You will need to give them a full list of all the I/O required.
